The ability to accurately track bulk material properties through a production chain or operational process chain is highly valuable. In the mining industry, having incorrect estimates of grade and quantity in stockpiles can lead to financial penalties. Improving the quality of information by tracking material at each stage would enable mine engineers to perform greater planning to avoid these penalties.
An example of a production chain and an operational process chain is an open-pit iron-ore mine. In open-pit iron-ore mining, material is excavated from specific locations after being blasted. The amount excavated from each location is usually determined by production requirements to meet a certain level of quality and quantity of material. The excavated material is transported by haul trucks directly to dumping stations for primary crushing or to stockpiles, from which the material is removed for further processing. Material is also removed to enable the development of the pit to access future deposits. Such material is transported to dumping locations which may or may not be permanent. The material dumped may be used as fill for previous excavations.
One practice in mining is estimate material in haul trucks by assuming they carry a common constant percentage of their maximum load. This value, termed a ‘load factor’, is essentially the average mass of material moved by trucks calculated over a long timeline. This method, although accurate over large time frames, is prone to fluctuations based on operator skill through over/under filling of trucks and excavation of material outside of designated areas. It also relies upon the quality of initial in-ground estimates of the material being excavated.
There is an ongoing need for a probabilistically consistent framework for estimating the properties of excavated material as it progresses through a mining production chain, for example from the point of excavation to railing stockpiles and beyond.
Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common general knowledge in Australia or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person skilled in the art.